BLUETOOTH technology may be utilized to create a virtual serial port to send messages between BLUETOOTH devices. The virtual serial port may be a communication channel established between the BLUETOOTH devices using a Serial Port Profile (SPP) radio frequency communication (RFCOMM) channel. The SPP may be specified by using a SPP universal unique identifier (UUID) predefined by the BLUETOOTH standard as 0x1101, or in its long form, as 00001101-0000-1000-8000-00805F9B34FB.
In many devices, a maximum number of supported RFCOMM/SPP channels may be limited to a small number, such as six. Thus, systems that desire the use of many RFCOMM/SPP virtual serial channels may encounter errors relating to one or more devices exceeding the maximum number of available RFCOMM/SPP virtual serial channels.
Multiplexing is a technique whereby multiple message sources or destinations may utilize a single RFCOMM/SPP BLUETOOTH channel. Multiplexing may be done to avoid errors relating to one or more devices exceeding the maximum number of available RFCOMM/SPP virtual serial channels.